Origin of Anomalous $C_{\mathrm {OSS}}$ Hysteresis in Resonant Converters With Superjunction FETs

Output capacitance (C
_OSS
) hysteresis has recently been discovered as a new source of power loss in resonant converters with advanced superjunction (SJ) FETs. This brief unveils the physical mechanism responsible for C
_OSS
hysteresis by means of mixed-mode simulations. A new physical effect, based on stranded charges, is observed in the SJ-FETs processed by multi-implant multiepitaxy with small cell pitch. The alternative trench-filling epitaxial growth is a process suitable to address the resonant converters due to its inherent immunity to the C
_OSS
hysteresis.